Let yourself be imperfect. Allow yourself to do something badly or messily in the spirit of creativity and fun.

Recall a funny memory and send a "remember when" email to a friend or family member. You'll likely brighten their day as well as your own.

Challenge your coworkers to a game of Scrabble (or basketball or whatever else tickles your game fancy). Nothing breaks up the monotony of the day like a little friendly competition.

Change your shoes. Keep flip flops or bunny slippers under your desk or near your front door and slip into them when you want to be reminded of relaxation mode.

Spend some play time with a pet. Obviously dogs and cats are easy marks, but I've had playful encounters with hummingbirds and squirrels who're peeking in my window. (Note: probably want to avoid playing with raccoons, coyotes, and mountain lions...)

Tune into Hulu during your lunch break. My favorite playful shows are New Girl, The Mindy Project, and Modern Family.

Go outside. Something about being outdoors always feels a little like you're playing hooky.

Hang out with children and go along with whatever they tell you to do. They're expert players. I once found my brother-in-law laying in a recliner having his teeth faux-cleaned by my niece who was playing dental hygienist. Classic.

Leave anonymous "love" notes around your home or office for people to find. You'll feel like you're playing a secret spy game and recipients' days will be made when they discover messages telling them they're wonderful and amazing.

Build something. A tower out of your loose change. A teepee out of the pens on your desk. A mosaic out of M&Ms. Again, building is a great way to tap into fun and creativity—the signature marks of play.

As I was compiling this list, my hubby and his best friend came into the room so I asked them how they like to add play to their work days. The reply I got was: Fart jokes.